Hostilities between right- and left-wing journals and blogs over the coverage of the Iraq war have claimed a fresh scalp after the New Republic magazine retracted a series of articles from a US soldier, saying it could no longer stand by his accounts.

The editor of the left-leaning magazine, Franklin Foer, has posted a 7,000-word description of the soul-searching that has consumed the magazine for the past four months over dispatches it published from Iraq by an army private.

The articles were carried from a pseudonymous author later revealed to be Scott Thomas Beauchamp, who was stationed just south of Baghdad.

The pieces captured the petty cruelty of war, from a scene of scavenger dogs eating corpses to a boy who craved to learn English but had his tongue cut out by Shia hardmen. The articles that sparked the furore described incidents of brutalised behaviour on the part of US personnel, including a soldier who revelled in running over dogs with his armoured car and another who paraded fragments of a child's skull on his head.

Questions were asked in July, initially from the right-of-centre Weekly Standard magazine and then through blogs. Foer said the magazine had asked Beauchamp for copies of the statements he gave to military investigators, to no avail. "In retrospect, we never should have put Beauchamp in this situation," he said. "He was a young soldier in a war zone, an untried writer without journalistic training."

Meanwhile, the website of the right-wing National Review has admitted posting two "misleading" reports from a former marine, Thomas Smith. One claimed that 5,000 Hizbullah fighters had deployed to Christian areas of Beirut.